This invention relates to the conversion of methane to higher hydrocarbons. A particular application of this invention is a method for converting natural gas to more readily transportable material.
Recently, it has been discovered that methane may be converted to higher hydrocarbons by a process which comprises contacting methane and an oxidative synthesizing agent at synthesizing conditions (e.g., at a temperature selected within the range from about 500.degree. to about 1000.degree. C.). Oxidative synthesizing agents are compositions having as a principal component at least one oxide of at least one metal which compositions produce C.sub.2 +hydrocarbon products, co-product water, and a composition comprising a reduced metal oxide when contacted with methane at synthesizing conditions. Reducible oxides of several metals have been identified which are capable of converting methane to higher hydrocarbons. In particular, oxides of manganese, tin, indium, germanium, lead, antimony, bismuth, praseodymium, terbium, cerium, iron and ruthenium are most useful. See commonly-assigned U.S. Pat. Nos. 4,443,649 (Mn); 4,444,984 (Sn); 4,445,648 (In); 4,443,645 (Ge); 4,443,674 (Pb); 4,443,646 (Bi); 4,499,323 (Pr); 4,499,324 (Ce); and 4,593,139 (Ru), the entire contents of which are incorporated herein by reference. See also commonly-assigned U.S. patent application Ser. No. 06/666,694 (Fe) the entire content of which is incorporated herein by reference.
Commonly-assigned U.S. Pat. No. 4,554,395 discloses and claims a process which comprises contacting methane with an oxidative synthesizing agent under elevated pressure (2-100 atmospheres) to produce greater amounts of C.sub.3 +hydrocarbon products.
Commonly-assigned U.S. Pat. No. 4,560,821 discloses and claims a process for the conversion of methane to higher hydrocarbons which comprises contacting methane with particles comprising an oxidative synthesizing agent which particles recirculate between two physically separate zones--a methane contact zone and an oxygen contact zone.
The reaction products of such processes are hydrocarbons, carbon oxides, coke and water. It would be beneficial in these processes to reduce selectivities to carbon oxides and coke and to increase methane conversions to the desired hydrocarbon products. Accordingly, an object of this invention is to provide an improved process for converting methane to higher hydrocarbons. More particular aspects, objects and the several advantages of this invention will become apparent to those skilled in the art upon reading this disclosure and the appended claims.